Java Chapter 2

Q. What is Java?

Ans:  Java is an object-oriented language that enables you to create real world applications. Java is the very popular technology in IT Industry .There are more and more Companies who are migrating their applications from current technologies to Java which leaves a huge empty space to be filled with Java and its technologies. The Java platform at its core is a way of computing that is based on the power of networks and the idea that the same software should run on different kinds of computers, consumer gadgets and other devices.

The architecture of network does not affect the java and this thing makes it a much significant language. The nature of Java technology is extremely important in a networked world where one cannot predict what kind of devices our partners, suppliers and employees may use to connect to you.

Java technology based software works just about everywhere from the smallest devices to super computers. It is even not affected by the kind of computer, phone, TV or operating system they run on. They work on any kind of compatible device that supports Java platform.

Q. Why Java Programming?

Ans:- Java Technologies provide an ideal entry into application development or software project management careers. Importance of Java as a coherent platform independent object oriented language is widely recognized .As we know, Oracle has become the custodian of Java through its acquisition of Sun Microsystems .Oracle-Java Certifications are among the most

sought after badges of credibility for expertise in the Information Technology marketplace. An Oracle-Java Technical Certification is a valuable, industry -recognized credential that signifies a proven level of knowledge and skill. This technology helps raise your visibility and increase your access to the industries most Challenging opportunities. Employers look for ways to distinguish employees and prospective Employees who have the solid foundation of skills needed for effective performance,

Scope of Java Programming

• Service industry
• Product industry
• Web application Development
• Banking
• Insurance
• Medical
• E-commerce
• Wireless
• Mobile phone applications

Q. Explain the Term Object Oriented Programming. 

Ans:-   As software systems begin to model more and more complex systems the most important problem that arises is maintenance. Software based conventional procedural languages suffer from the problem that they become cumbersome to design and maintain as complexity of the system to be modeled increases. Object-Oriented Programming (OOP) has been developed, based on real life itself, to easily and efficiently remove the problems associated with procedural programming.

The first achievement of OOP towards better design and maintenance is the removal of ambiguity, resulting in consistency of perception. Let us consider an example. If someone were to ask what “5” represents, replies can vary from “five”, and “an odd number” to “a number greater than 4 and less than 6”. This difference in perception of the same entity could lead to confusion. If at this level there is such confusion, what will happen if the situation becomes more and more complex?

OOP resolves this problem by categorizing data into classes such that a class represents a specific identity. For the above example we can create a class named, odd_number, defining “5” as an instance of it to remove the ambiguity of perception.

The next problem that OOP handles is the problem of non-flexibility of code. In procedural programming, parts of code are interdependent. This interdependency, or degree of coupling, lowers the flexibility in modification and manipulation of a particular part of the program without affecting the other parts. Another related problem associated with the procedural approach is low degree of cohesion, which means that adding more functionality to a certain part of code becomes almost impossible without affecting the other interdependent parts.

Let’s take an example of a room whose capacity is of 10 people, each person being allocated a certain amount of space. Now, 5 more people come, and they have to be accommodated. How can we do this? We cannot increase the size of the room without affecting the other rooms adjacent to it. We see that this interdependency puts limits on our ability to increase the size of the room. Thus, the stress in the design of systems is on reduction of interdependence, or a low degree of coupling. Although coupling cannot be totally eliminated, OOP tries to minimize it. A solution to the above example of accommodating 5 more people could be to reduce the amount of space allocated to each person by distributing it among the 15 persons. That is what OOP does. It provides maximum degree of cohesion by adding functionality to the existing code (with the help of a special feature, inheritance) without interfering with others. Inheritance and another feature, polymorphism, make the code easily re-usable and extensible. This is not possible with the structured approach, where the only way to re-use code is to repeatedly copy the code wherever required and edit it. This procedure is usually error prone. OOP removes this problem.

In conventional procedural programming, more stress is laid on the procedure rather than the data involved. Now suppose, two different people are making two different modules of a software, independent of each other, and after completion of their module they integrate their modules. They may find that the program does not run as excepted. The problem may be that they are using the same variable names in their modules or accessing a single global data and using it with changed values. Thus the security of data is always at a risk in the procedural approach. In the object-oriented approach, data is treated as the most important part of the program and can be hidden to limit access and prevent mishandling.